Complete androgen insensitivity syndrome (CAIS) occurs in individuals whose cells cannot properly respond to androgens. Androgens are hormones (chemicals) that are responsible for male characteristics. When cells do not respond to androgens, they cannot do the work to cause the body to develop like it is supposed to. Complete androgen insensitivity syndrome is the most extreme of the three types of androgen insensitivity syndromes. It occurs in 1 in 20,000 individuals. People with this disorder have an X and a Y chromosome typical of a male, but develop as a female. Symptoms of complete androgen insensitivity syndrome include internal testes, a shortened vaginal depth, and infertility. CAIS is not usually diagnosed until puberty when a lack of menstruation and other changes are observed. There is no treatment for CAIS, but symptoms can be managed with medications, surgery, or therapy. Because complete androgen insensitivity syndrome involves a person's gender identity, each individual with CAIS may choose a different method of management after consulting with a genetic counselor.